The study is dated June 2012 and is based on Lana`i data from 2005 & 2008.

The authors considered four centralized options using diesel, wind, solar, and batteries.

Surprise! The study found that the optimal solution is adding wind to the existing diesel generators.

One problem is that when wind is a large percentage of the total mix, then sudden wind speed changes can have great impact on the total system. The costs of system controls needed to offset wind variability was not included in the study.

Another problem is that the authors opted for analyzing batteries using a vanadium redox flow battery (VRB). This type of battery is currently not economically nor commercially viable. In the middle of the study they had to switch battery types when “the VRB flow battery was no longer available.”

Options not examined included:

(a) Distributed Generation;

(b) supplying Lana`i with power from O`ahu or Maui via a two-way inter-island cable;

(c) replacing the use of diesel with liquefied natural gas (LNG); and

(d) the use of Pumped Storage Hydro, the dominant battery in the national grid accounting for 99.9% of all energy storage in the nation.

How many drafts of the report were there? What was the hold-up?

The Study was released in 2012. “The initial analysis used solar and wind resource data and load data from 2005” although “newer resource data from 2008 was also used.”